Current photonics ranging devices may be limited to a single application for which they are optimized. For example, these applications can include single or multi-zone ranging systems. Furthermore, these single and multi-zone ranging systems can be divided into shorter range (e.g. 0-30 cm) and longer range (e.g. from 30 cm) detecting systems. Depending on the application, the output of the light source should be controlled in such a way as to satisfy this application. This may inherently make the device unsuitable for alternative applications.
For example, a photonics ranging device application may use time of flight (TOF) to determine a distance between a reflective object and the device. In TOF, a pulse of light is emitted and reflected off an object back to a sensor. The time taken for the light to travel to the object and be reflected back onto a sensor may be used to determine the distance between the object and the device based on the known speed of light.
The photonic device and the TOF calculations may be implemented in applications where it is useful to know the distance between an object and the device. One example is in mobile telephones incorporating touch screens. In this application, when receiving or making a phone call, part of a user's face may touch the touchscreen to place the ear in the vicinity of the speaker. During the call, the touchscreen should be non-responsive to the user's face to prevent accidental hanging up. Time of flight calculations may be carried out to determine that this is the case and to disable the touch screen. However, such a device may not be optimized or designed to be used in application where longer range detection is required. For example, one long range application is to use the photonic device in the same mobile telephone to determine an object's motion away from the mobile phone and thus enable gesture control of the mobile telephone.